Variation among users

A further complication is the wide variability among people to VR sickness susceptibility. Accounting for individual differences among groups must be accounted for in the design of the experiment; see Section 12.4. Most researchers believe that women are more susceptible to motion sickness than men [145,245]; however, this conclusion is disputed in [173]. Regarding age, it seems that susceptibility is highest in children under 12, which then rapidly decreases as they mature to adulthood, and then gradually decreases further over their lifetime [266]. One study even concludes that Chinese people are more susceptible than some other ethic groups [314]. The best predictor of an individual's susceptibility to motion sickness is to determine whether she or he has had it before. Finally, note that there may also be variability across groups as in the severity of the symptoms, the speed of their onset, the time they last after the experiment, and the rate at which the users adapt to VR.